Hot-Dip Galvanized Channel Steel | 6.3# – 40#, 30–700 g/m²
Hot-rolled channel steel hot-dip galvanized to EN ISO 1461, ASTM A123 or GB/T 13912, with a zinc coating from 30 to 700 g/m² covering the inside of the section as well as the outside. Sizes 6.3# to 40# in Q235B and Q355B base grades, cut and drilled to your drawing before dipping.
Product Overview
Galvanized channel steel — also called galvanized U-channel or C-channel — is a hot-rolled channel that has been immersed in molten zinc so a bonded zinc-iron alloy coating forms over the entire section. The advantage over painted channel is most obvious on the inside of the U: a paint film applied to an open section struggles to coat the web-to-flange junction thoroughly and is easily damaged in handling, while hot-dip galvanizing coats every surface the zinc can reach, including that internal corner.
The coating protects the steel sacrificially rather than as a barrier, which means a scratch, a cut end or a drilled bolt hole does not become a corrosion initiation point. That is why galvanized channel is the standard choice for purlins, framing and supports in coastal, humid and industrial atmospheres where the structure cannot be taken out of service to be repainted.
Stock covers 6.3#, 8#, 10#, 12#, 14#, 16#, 18#, 20#, 22#, 25#, 28#, 32#, 36# and 40# over Q235B and Q355B base. Coating weight is nominated against the service environment and quoted as the total on both surfaces, with a coating mass test report issued for each lot alongside the mill certificate for the base steel.
Specifications & Size Range
Galvanized channel range with the coating weights normally nominated for each exposure class. Mill lengths are 6 m, 9 m and 12 m; cutting, notching and drilling are completed before galvanizing. High-coating weights up to 700 g/m² are produced to order.
| Size group | Designations | Web height (mm) | Coating weight (g/m², both surfaces) | Typical use |
|---|---|---|---|---|
| Light channel | 6.3#, 8#, 10#, 12# | 63 – 120 | 180 – 275 | Roof and wall purlins, framing, cable supports, guards |
| Medium channel | 14#, 16#, 18#, 20# | 140 – 200 | 275 – 400 | Coastal building framing, plant supports, walkway frames |
| Heavy channel | 22#, 25#, 28# | 220 – 280 | 275 – 500 | Quay supports, gantry framing, transport equipment |
| Large channel | 32#, 36#, 40# | 320 – 400 | 350 – 700 | Marine structures, heavy outdoor frames, bridge members |
| High-coating channel | Any size above | as above | 500 – 700 | Severe marine, chemical and high-humidity atmospheres |
Tolerances
Zinc coating to GB/T 13912, EN ISO 1461, ASTM A123 / A153 and JIS H8641, quoted in g/m² total on both surfaces, with a working guide of about 7 µm of coating thickness per 100 g/m². Base channel dimensions, straightness and mass follow GB/T 706. Coating mass is measured on a sample basis per lot and a test report is issued with the shipment.
Steel Grades & International Equivalents
All grades below are supplied with a mill test certificate. The right-hand column shows the material type and the Chinese standard the grade is produced to; the middle columns give the nearest recognised equivalent in other national standards. Exact equivalence for a specific project should be confirmed on the enquiry.
| GB (China) | ASTM / AISI (US) | EN (Europe) | JIS (Japan) | DIN (Germany) | Type / Standard |
|---|---|---|---|---|---|
| Q235B + hot-dip galvanized | A123 / A153 (ASTM) | EN ISO 1461 | JIS H8641 | DIN 50976 | Hot-dip galvanized structural steel (GB/T 13912) |
| Q235B | A36 / A283 Gr.C | S235JR (EN 10025-2) | SS400 (JIS G3101) | St37-2 | Carbon structural steel (GB/T 700) |
| Q355B | A572 Gr.50 / A992 | S355JR (EN 10025-2) | SM490 (JIS G3106) | St52-3 | High-strength low-alloy (HSLA) steel (GB/T 1591) |
Grade Notes
- Q235B + hot-dip galvanized — Zinc coating of 30–700 g/m² gives 5–30+ years of atmospheric corrosion protection depending on thickness and environment.
- Q235B — The workhorse structural grade in China. Fully weldable, excellent cost-performance, the closest Chinese equivalent to ASTM A36 / EN S235JR.
- Q355B — High-strength structural steel for heavy structures, bridges and towers. Equivalent to ASTM A572 Gr.50 / EN S355JR.
Chemical Composition (%, ladle analysis)
Typical specification limits. Actual heat values are reported on the mill test certificate supplied with every shipment.
| Grade | C | Si | Mn | P max | S max | Other elements |
|---|---|---|---|---|---|---|
| Q235B | ≤0.20 | ≤0.35 | ≤1.40 | ≤0.045 | ≤0.045 | — |
| Q355B | ≤0.24 | ≤0.55 | ≤1.60 | ≤0.035 | ≤0.035 | Ceq ≤0.45 |
Mechanical Properties
Minimum values at room temperature unless stated. ReL = yield strength; Rp0.2 = 0.2% proof stress; Rm = tensile strength; A = elongation after fracture.
| Grade | Yield (ReL) | Proof (Rp0.2) | Tensile (Rm) | Elongation A | Impact / others | |
|---|---|---|---|---|---|---|
| Q235B + hot-dip galvanized | — | — | — | — | — | Coating 30–700 g/m² (both sides), made to order Adhesion per GB/T 13912 bend test |
| Q235B | ≥235 MPa | — | 370–500 MPa | ≥26% | +20 °C, ≥27 J | — |
| Q355B | ≥355 MPa (≤16 mm) | — | 470–630 MPa | ≥22% | +20 °C, ≥27 J | — |
Standards & Documents
- GB/T 13912 — hot-dip galvanized coatings on fabricated iron and steel articles
- EN ISO 1461 / ISO 1461 — hot-dip galvanized coatings (international equivalent)
- ASTM A123 / A153 — zinc (hot-dip galvanized) coatings on iron and steel products
- JIS H8641 — hot-dip zinc coatings (Japanese equivalent)
- GB/T 706 — base channel dimensions, shape, mass and tolerance
- Zinc bath to EN 1179 (Zn ≥ 99.995%); coating mass test report with every lot; EN 10204 3.1 mill certificate for the base channel
Typical Applications
| Industry / Application | Typical use |
|---|---|
| Coastal industrial buildings | Purlins, side rails, crane supports and plant framing on sites where salt-laden air would destroy a paint system within a few years. |
| Power & electrical outdoor works | Substation supports, cable tray and ladder supports, transformer plinth framing and outdoor distribution structures, where coating weight is set by the corrosion class. |
| Road & municipal infrastructure | Guard-rail supports, sign gantry framing, pedestrian barrier members, lamp post brackets and drainage supports. |
| Chemical & water treatment plants | Pipe supports, equipment platforms, tank framing and walkway supports in damp, chemical or wash-down environments. |
| Solar & PV support structures | Rail and purlin sections for ground-mount arrays, where a 25-year service life is expected and repainting is not practical. |
| Agricultural & livestock structures | Barn and greenhouse framing, pen divisions and feed handling supports in humid or ammoniacal conditions. |
| Racking, work platforms & shelving | Storage racking frames, mezzanine and walkway framing and work platforms where the bright galvanized finish is the final appearance. |
Common Problems Buyers Face — and How We Prevent Them
These are the issues that most often cause claims on steel imports. Each one is controlled in our process before shipment.
White rust between bundled channels after a long voyage
Why it happens: Moisture trapped inside the channel and between bundled members reacts with the zinc surface, producing a white film that looks like a defect on arrival.
Our control: Bundles are packed with spacers and stowed so water can drain from the section, shipped dry, with VCI paper on long or humid routes. Chromate passivation is available for appearance-critical orders; a light white film can be washed off and does not reduce coating life.
Coating mass below specification inside the channel
Why it happens: The internal corner between the web and the flanges is the last place to fill during dipping, so a short dip time leaves a thin coating exactly where corrosion tends to start.
Our control: Channel is jigged so the section drains and fills correctly, dipping time and bath temperature are set for the section, and coating mass is checked on a sample basis per lot and reported against the specified minimum average.
Distortion along the length of a galvanized channel
Why it happens: The dipping thermal cycle releases rolling stress, and channel is asymmetric so it bows more readily than a symmetric section.
Our control: Jigging, dip orientation and cooling are controlled for long sections, and straightness is checked after galvanizing against the standard. For distortion-sensitive members we will propose an alternative section at enquiry stage.
Site welding leaves bare steel at the connection
Why it happens: The connection is welded after galvanizing, and welding burns the coating away in the most heavily stressed part of the joint.
Our control: Members are cut, notched and drilled before dipping so bolted connections can be used throughout. Where site welding is unavoidable, the weld zone must be cleaned and treated with zinc-rich repair paint, and compatible touch-up material can be supplied with the order.
Coating damaged while unloading at the destination port
Why it happens: Channels lifted with chains or dragged across one another abrade the coating on flange tips and edges, and each damaged area is a potential corrosion start.
Our control: Bundles are lifted with belt or nylon slings on protected contact points, timber separators are placed between layers, and repair material for minor transit damage is supplied with the shipment.
Our Supply & Manufacturing Advantages
- Coating that reaches the inside of the section — Hot-dip galvanizing coats the web-to-flange junction where paint struggles, which is the area that decides the service life of an open section.
- Coating weight nominated, not guessed — From 180 g/m² for general outdoor service up to 700 g/m² for severe marine exposure, quoted as the total on both surfaces.
- High-coating option available — Coating weights equivalent to a 70 µm layer and above can be produced for the most aggressive sites, where standard galvanizing would be marginal.
- Processed before dipping — Cut, notched and drilled to your cutting list before galvanizing, so the finished member has coated ends and holes and needs no site rework.
- Documented steel and coating — EN 10204 3.1 mill certificate for the base channel and a coating mass test report for the zinc layer with every lot.
- Maintenance-free outdoor service — No painting, inspection or repainting cycle for the life of the structure, which is where the whole-life saving is actually realised.
Packaging, Delivery & Payment
- Packing: loose in bulk vessel, or bundled and containerised to your requirement. Galvanized and coated products get VCI paper, waterproof wrapping and edge protection. See our export packaging methods.
- Availability: both stock and custom production. Tell us the specification and we will confirm the route.
- MOQ: no strict minimum — one ton can ship.
- Lead time: stock dispatched to port within 3 days; orders needing export packaging about 1 week; custom production quoted per product.
- Payment: stock — 10% deposit, balance before shipment; custom production — 50% deposit, balance before shipment.
- Documents: EN 10204 3.1 mill test certificate with every shipment; third-party inspection (SGS / BV) on request.
Frequently Asked Questions
How heavy a zinc coating should I specify on galvanized channel?
For dry indoor service 60 to 100 g/m² is adequate; for general outdoor inland exposure 180 to 275 g/m²; for coastal and industrial atmospheres 350 to 500 g/m²; and for severe marine or chemical exposure 600 to 700 g/m². The figure is the total on both surfaces and corresponds to roughly 7 µm per 100 g/m². Tell us where the structure will stand and we will nominate the weight.
What is the Chinese equivalent of EN S235JR for galvanized channel?
Q235B to GB/T 700 is the base grade closest to S235JR and is what we galvanize for the European market, referenced in our library as S235-GALV. Where a higher strength is needed, the base is Q355B, the equivalent of S355JR. Both are supplied with the mill certificate and the grade equivalence in writing.
Can galvanized channel steel be welded?
It can, but welding burns away the zinc in and around the weld and leaves bare steel that must be protected. Wherever possible the member should be welded before galvanizing, or the connection should be bolted. If field welding is unavoidable, clean the weld and adjacent zone and apply zinc-rich repair paint, and we can supply compatible touch-up material with the order.
How much more does galvanized channel cost than black channel?
The galvanizing step typically adds around 20 to 30 percent to the material price, depending on the coating weight and the section, but it removes the cost of blasting, priming, painting, inspection and the repainting cycle. On an outdoor or coastal project with a long design life, the whole-life cost is normally lower, and we can set out the comparison on request.
Who supplies galvanized channel steel from China?
We supply hot-dip galvanized channel from 6.3# to 40# over Q235B, Q355B and S235-GALV base grades, with coating weights nominated against the exposure class, processing to your cutting list before dipping and a coating mass test report per lot. Send the section list, the coating specification and the destination port for a quotation.
Does the zinc coating change the mechanical properties of the channel?
No. Galvanizing takes place at around 450 °C, well below the temperature at which the microstructure of Q235B or Q355B structural steel would change, so yield strength, tensile strength and stiffness are unaffected. The mill certificate issued for the base channel remains valid for the galvanized product.
Will galvanized channel rust at cut ends or drilled holes?
Not if cutting and drilling are done before galvanizing, which is how we supply it as standard. If the material is cut on site after coating, the exposed steel will initially be protected by the zinc around it but should be touch-up coated for long-term service. Cutting and drilling before dipping is one of the main reasons to buy processed rather than plain lengths.
What is the minimum order quantity?
No strict minimum and one ton can ship. Because galvanizing is a bath process, small quantities are usually grouped into a load, so we will confirm the real lead time instead of promising an immediate dispatch.
How is galvanized channel packed for export?
Bundled with the flanges nested and steel straps sized for container loading, or shipped loose in a bulk vessel for large tonnage. Spacers allow air to move through the pack and water to drain from the section, flange tips are protected against abrasion, and the pack is lashed so members cannot rub during the voyage.
Request a Quotation Export Packaging
Live Stock & Indicative Price
The table below lists live stock at the time of publication, with indicative EXW China reference prices in USD per tonne (converted at 6.70 CNY/USD). Steel prices move with the mill market every week — send us your size, quantity and destination and we will confirm availability and issue a firm FOB or CIF quotation.
| Product | Size / Model | Grade | Weight / pc | Price (USD/t, EXW) | Stock (t) |
|---|---|---|---|---|---|
| Galvanized Channel Steel | U63 | Q235B | 19–20 kg | $572 | 2 |
| Galvanized Channel Steel | U63 | Q235B | 20–21 kg | $570 | 2 |
| Galvanized Channel Steel | U63 | Q235B | 21–22 kg | $569 | 3 |
| Galvanized Channel Steel | U63 | Q235B | 22–23 kg | $561 | 1 |
| Galvanized Channel Steel | U63 | Q235B | 23–24 kg | $558 | 2 |
| Galvanized Channel Steel | U63 | Q235B | 24–25 kg | $554 | 1 |
| Galvanized Channel Steel | U63 | Q235B | 25–26 kg | $551 | 2 |
| Galvanized Channel Steel | U63 | Q235B | 26–27 kg | $546 | 4 |
| Galvanized Channel Steel | U63 | Q235B | 27–28 kg | $545 | 4 |
| Galvanized Channel Steel | U63 | Q235B | 28–29 kg | $543 | — |
| Galvanized Channel Steel | U63 | Q235B | 29–30 kg | $537 | 1 |
| Galvanized Channel Steel | U63 | Q235B | 30–31 kg | $536 | 4 |
| Galvanized Channel Steel | U63 | Q235B | 31–32 kg | $536 | — |
| Galvanized Channel Steel | U63 | Q235B | 32–33 kg | $534 | 4 |
| Galvanized Channel Steel | U63 | Q235B | 33–34 kg | $531 | 4 |
| Galvanized Channel Steel | U63 | Q235B | 34–35 kg | $530 | 5 |
| Galvanized Channel Steel | U63 | Q235B | 35–36 kg | $528 | 5 |
| Galvanized Channel Steel | U63 | Q235B | 36–37 kg | $528 | 5 |
| Galvanized Channel Steel | U80 | Q235B | 23–24 kg | $572 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 24–25 kg | $569 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 25–26 kg | $564 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 26–27 kg | $561 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 27–28 kg | $557 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 28–29 kg | $549 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 29–30 kg | $545 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 30–31 kg | $543 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 31–32 kg | $540 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 32–33 kg | $537 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 33–34 kg | $536 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 34–35 kg | $536 | 120 |
| Galvanized Channel Steel | U80 | Q235B | 35–36 kg | $533 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 36–37 kg | $530 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 37–38 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 38–39 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 39–40 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 40–41 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 41–42 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 42–43 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 43–44 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 44–45 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 45–46 kg | $527 | 80 |
| Galvanized Channel Steel | U80 | Q235B | 46–47 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 30–31 kg | $572 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 31–32 kg | $570 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 32–33 kg | $569 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 33–34 kg | $561 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 34–35 kg | $558 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 35–36 kg | $554 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 36–37 kg | $551 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 37–38 kg | $546 | 100 |
| Galvanized Channel Steel | U100 | Q235B | 38–39 kg | $545 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 39–40 kg | $543 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 40–41 kg | $537 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 41–42 kg | $536 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 42–43 kg | $536 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 43–44 kg | $534 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 44–45 kg | $531 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 45–46 kg | $530 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 46–47 kg | $528 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 47–48 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 48–49 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 49–50 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 50–51 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 51–52 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 52–53 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 53–54 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 54–55 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 55–56 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 56–57 kg | $527 | 80 |
| Galvanized Channel Steel | U100 | Q235B | 57–58 kg | $527 | 80 |
Showing 70 of 70 listed sizes. Price range USD 527–572 per tonne (EXW China). MOQ from 1 tonne; stock dispatched to port within 3 days. Mill test certificate (EN 10204 3.1) and third-party inspection available on request.